<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
<div id="app">
    <span v-pre>{{msg}}</span>
    <br>
    <span v-once>{{msg}}</span>
    <br>
    <span>{{msg}}</span>
</div>
<script src="vue.js"></script>
<script>
        var vm=new Vue({
            el:'#app',
            data:{
                msg:'this will bot be compiled'
            }
        })
</script>
</body>
</html>